shrapnel wrote:Hmmm.... maybe no worms in THIS Can !zullil wrote:Please see my reply. Specifically, the part about canned worms.Dirt wrote:You neglected to explain how to test. Nodes/second is not the right metric.zullil wrote:You'll have to test for yourself.
I got 2-3 pretty MASSIVE wins against reasonably strong opponents after enabling HT on my i7 5960 X.
But then again, I usually win anyway, so can't say for sure.
I made the compiles from the Link you provided, using the Stockfish Rockwood BYO software.
Using 16 Threads with HT On may or may not be helping, but I certainly see no fall in ELO.
Here's one of the games... I was Black.
[pgn]
[Event "120s/Move"]
[Site "www.come2play.com"]
[Date "2015.02.16"]
[Round "?"]
[White "Stockfish"]
[Black "Stockfish 160215 64 BMI2"]
[Result "0-1"]
[ECO "C88"]
[PlyCount "69"]
{8192MB, KINGASAD V5.ctg, Anil} 1. e4 {0} e5 {B 0} 2. Nf3 {33} Nc6 {B 0} 3. Bb5
{22} a6 {B 0} 4. Ba4 {18} Nf6 {B 0} 5. O-O {22} Be7 {B 0} 6. Re1 {29} b5 {B 0}
7. Bb3 {19} O-O {B 0} 8. h3 {23} Bb7 {B 0} 9. d3 {19} d5 {B 0} 10. exd5 {25}
Nxd5 {B 0} 11. Nxe5 {21} Nd4 {B 0} 12. Nc3 {21} Nb4 {B 0} 13. Ne4 Nxb3 {0.00/
33 72} 14. axb3 {0.06/25 1} Qd5 {0.11/35 104} 15. f4 f6 {-0.27/34 69} 16. Nf3 {
-0.29/27 1} f5 {-0.42/37 89} 17. Nf2 {-0.31/25 1} Qd8 {-0.41/37 97} 18. Re3 Bd6
{-0.37/36 87} 19. c3 {-0.29/25 1} Nd5 {-0.39/37 76} 20. Re1 {-0.39/28 1} Bxf4 {
-0.43/37 90} 21. d4 {-0.39/23 1} Bg3 {-0.53/35 105} 22. Re6 {-0.46/30 8} Nf6 {
-0.40/35 96} 23. Nd3 {-0.42/25 1} Ne4 {-0.39/34 91} 24. Bf4 {-0.52/31 11} Qd7 {
-0.62/36 99} 25. d5 Qxd5 {-0.54/36 89} 26. Re5 {-0.54/25 1} Qf7 {-0.74/39 92}
27. Bxg3 {-0.72/30 2} Nxg3 {-0.66/39 87} 28. Nc5 {-0.67/27 1} Rad8 {-0.64/41 90
} 29. Nd4 {-0.64/25 1} Rd5 {-0.60/41 101} 30. Rxd5 Bxd5 {-0.88/37 78} 31. Rxa6
Re8 {-1.44/35 52} 32. Nde6 c6 {-1.46/35 33} 33. Nf4 {-1.46/28 1} Qe7 {-1.91/38
67} 34. Ncd3 {-1.78/36 22} Bf7 {-1.91/39 86} 35. Qf3 {-2.03/39 55} 0-1
[/pgn]
Stockfish with 16 threads --- big news?
Moderators: hgm, Rebel, chrisw
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Re: Stockfish with 16 threads --- big news?
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Re: Stockfish with 16 threads --- big news?
Hmm: +6 ELO for 8 cpu and +50 ELO for 16 cpu. This means +400 ELO for 32 cpu !?
Jouni
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Re: Stockfish with 16 threads --- big news?
@zullil, how are you able to show the game with chessboard and all ?
Please explain.
I couldn't figure it out.
Please explain.
I couldn't figure it out.
i7 5960X @ 4.1 Ghz, 64 GB G.Skill RipJaws RAM, Twin Asus ROG Strix OC 11 GB Geforce 2080 Tis
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Re: Stockfish with 16 threads --- big news?
See http://www.talkchess.com/forum/viewtopi ... 72&t=46462shrapnel wrote:@zullil, how are you able to show the game with chessboard and all ?
Please explain.
I couldn't figure it out.
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Re: Stockfish with 16 threads --- big news?
The contents of the can of worms without taking sides:
Hyperthreading turns 1 core into a virtual 2 cores that share computational resources. How much that actually speeds up a program in terms of nps will vary depending on the program. But then you have the waste of a parallelised alpha-beta search such that more nps at 16 cores is not necessarily better than the reduced amount at 8 cores.
Somewhere around 20% more nps was the number i've seen to break even. if you're getting 30% more nps it's probably an improvement to be running it under hyperthreading.
Hyperthreading turns 1 core into a virtual 2 cores that share computational resources. How much that actually speeds up a program in terms of nps will vary depending on the program. But then you have the waste of a parallelised alpha-beta search such that more nps at 16 cores is not necessarily better than the reduced amount at 8 cores.
Somewhere around 20% more nps was the number i've seen to break even. if you're getting 30% more nps it's probably an improvement to be running it under hyperthreading.
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Re: Stockfish with 16 threads --- big news?
@ zullil... correction....OK, HT NOT good....just barely managed to escape with Draw against weak player !
So, its HT Off from now on.
So, its HT Off from now on.
i7 5960X @ 4.1 Ghz, 64 GB G.Skill RipJaws RAM, Twin Asus ROG Strix OC 11 GB Geforce 2080 Tis
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Re: Stockfish with 16 threads --- big news?
A few years ago,
I tested in Auto232 mode: Houdini 2.0c with HT OFF and with HT ON
And I noticed no any BIG Elo difference...
For example, when HT ON was enabled, the CPU temperatures were approx.10C higher....that was the BIG difference ))
For Full Standings:
http://www.sedatcanbaz.com/chess/?page_id=1020
Best,
Sedat
I tested in Auto232 mode: Houdini 2.0c with HT OFF and with HT ON
And I noticed no any BIG Elo difference...
For example, when HT ON was enabled, the CPU temperatures were approx.10C higher....that was the BIG difference ))
Code: Select all
Rank Name Elo + – Games Score Oppo. Draws
1 Houdini 2.0c Pro x64 6c 3423 19 18 1008 70% 3261 42%
2 Houdini 2.0c Pro x64 12t 3421 16 16 1399 70% 3281 38%
http://www.sedatcanbaz.com/chess/?page_id=1020
Best,
Sedat
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Re: Stockfish with 16 threads --- big news?
Looks like some new variables were introduced, however, which is exactly the kind of thing that can cause this mysterious performance alteration.Vinvin wrote:Here's what was changed : https://github.com/zamar/Stockfish/comp ... ...942d67abob wrote:I'd bet that is a cache-alignment issue or something similar, if you add anything to a data structure, you can see unexpected performance losses (or gains) just because of the alignment that changes so easily. That could probably be fixed by looking at what was added and analyzing the memory around the changes to see what is different.Joerg Oster wrote:Yes.bob wrote:Looking at what the code affected, I don't see how it would slow down anything in a non-parallel search... did you compile old and new yourself, using the same makefile and compiler, and tested with the same exact settings???Joerg Oster wrote:Though it is a non-functional change on one core, I experience a small slowdown on my box.Michel wrote:That's extremely unlikely given that it is a non-functional change on one core. It's probably just an unlucky run.is the smp patch a regression for one core? or am I reading the test results wrong
EDIT: Actually checking again I see that the test wasn't even finished. Never draw conclusions from an unfinished test (statistics 101).
But I guess even a small elo-loss on one core of 1 or 2 elo would be acceptable, given the huge gain for 16 cores.
Here is a comparison of both versions with standard bench command, 20 runs each simultaneously:
Code: Select all
Engine | Nodes/second sf-default | 1682087.0 +- 3375.84 sf-smp | 1625325.0 +- 1962.36 Differences | 56762.0 +- 1505.0 Variance of the mean | 336.53 ( 0.59 %) Speed up | 3.49 %
Only some conditions when nb threads >= 2
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Re: Stockfish with 16 threads --- big news?
Or more !Troll wrote:Hmm: +6 ELO for 8 cpu and +50 ELO for 16 cpu. This means +400 ELO for 32 cpu !?
Troll²
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Re: Stockfish with 16 threads --- big news?
If I continue the sequence I getJouni wrote:Hmm: +6 ELO for 8 cpu and +50 ELO for 16 cpu. This means +400 ELO for 32 cpu !?
+3000 elo for 64 cpu
+20,000 elo for 128 cpu
+100,000 elo for 256 cpu
+0,000,000 elo for 512 cpu